DE60302896T2 - CONNECTING AGENT FOR SETTING AN ELECTRICAL CONNECTION BETWEEN A CELL, ESPECIALLY A LIQUID CRYSTAL CELL, AND A POWER SUPPLY OR CONTROLLER - Google Patents

Abstract

An electro-optical cell, in particular a liquid crystal display cell (2) or electrochemical photovoltaic cell, comprises: (a) a first front transparent substrate (4); (b) a second rear substrate (6) which may also be transparent; (c) the substrates are joined by a sealing frame delimiting a volume (8) for confining a sensitive substance with optical or electrical properties that can be modified; (d) the substrates incorporate electrodes (14, 16) destined to be connected to an power or control circuit. The sealing frame comprises a structured partition (12) on one of the substrates with its internal lateral surface delimiting the volume containing the sensitive substance. The substrates are assembled by a sealing joint (3) which occupies the interstice (28) delimited by the substrates and the outer lateral surface of the partition. The electrodes include bump contacts (20) of an electrical conducting material on the extension of each electrode at the point where they project from the partition to increase the surface of electrical contact with the power or control circuit. An Independent claim is also included for the fabrication of this electro-optical cell.

Description

The The present invention relates to connecting means comprising an electrical Connection between an electro-optical cell, such as a liquid crystal cell, or an electrochemical photovoltaic cell, and an external electronic supply or control circuit to produce. The invention relates to a Procedure for the production of such cells.

A the first known category of photovoltaic cells is transforming this Light in electricity by exploiting the photovoltaic effect at the junction of semiconductor materials occurs. The semiconductor material fulfills simultaneously the function of absorbing the light and separating the resulting electric charges (electrons and holes). The material must have a size Purity, free from defects, otherwise electrons recombine and holes, before they could be separated. The manufacturing cost of such Cells are therefore quite high.

The The present invention is directed to a method of making a second type of so-called electrochemical photovoltaic cells, which comprise a semiconductor material that is normally due to the size of his bandgap against the visible light is insensitive and only in the near Ultraviolet begins to absorb. Such a material can by the adsorption of a coloring agent or dye such as a complex of a transition metal containing a Percentage of conversion between an incident photon and a approaching the unit Electron allows Nevertheless, after being sensitized by the absorption of a Photons was stimulated, the dye can be an electron in the Transfer conduction band of the semiconductor material. That inside the Semiconductor material prevailing electric field allows the Extraction of this electron. After the transfer of the electron returns the colorant back to the oxidized ground state. The recombination between the electron in the conduction band of the semiconductor material and the hole on the oxidized colorant is much slower than the reduction of the oxidized colorant through an intermediary. Therefore, the charge separation is effective.

The Cells of the type described above generally comprise a first, translucent, front substrate and a second, rear substrate which also be translucent may or not. These two substrates each include theirs facing surfaces a first electrode, which is also called the counter electrode, and a second electrode, usually known as the photoelectrode. These electrodes should with an electrical supply circuit are connected and are classic in the form of a thin layer a conductive, translucent Oxides such as a mixture of indium / tin oxide or tin / antimony oxide educated.

The two substrates are interconnected by an encapsulation frame connected, which is longitudinal the scope of these extends. This encapsulation framework defines a dense volume for the Encapsulation of the semiconductor material, which in one layer on one the substrates is deposited, and an electrolyte, the above mentioned Contains intermediary.

• – mindestens ein erstes, vorderes, lichtdurchlässiges Substrat, dessen obere Oberfläche die vordere Fläche der Zelle bildet;
• – mindestens ein zweites, hinteres Substrat, das auch lichtdurchlässig sein kann oder nicht und dessen untere Oberfläche die hintere Fläche der Zelle bildet;
• – wobei die Substrate jeweils auf ihren einander zugewandten Flächen mindestens eine Elektrode umfassen, wobei diese Elektroden dazu vorgesehen sind, mit einer Steuerschaltung der Anzeige verbunden zu werden, die durch Anlegen von geeigneten elektrischen Spannungen an ausgewählte Elektroden imstande ist, die Durchlass- oder Reflexionseigenschaften einer optisch aktiven Umgebung zu modifizieren;
• – wobei die Substrate durch einen Einkapselungsrahmen vereinigt sind, der ein dichtes Volumen für die Einkapselung der optisch aktiven Umgebung begrenzt, und
• – Verbindungsmittel zum Herstellen der elektrischen Verbindung zwischen jeder Elektrode und der Steuerschaltung der Anzeige. Ein ständiges Problem auf dem Gebiet der elektrochemischen photovoltaischen Zellen der vorstehend beschriebenen Art wird durch die Verbindungsmittel aufgeworfen, die zum Herstellen der elektrischen Verbindung zwischen den Elektroden der Zelle und einer elektrischen Versorgungsschaltung verwendet werden. Dieses Problem wird auch bei den elektrooptischen Anzeigezellen angetroffen, bei denen die Elektroden der Zelle mit der Generatorvorrichtung für elektrische Steuersignale verbunden werden müssen, die die optischen Eigenschaften des empfindlichen Materials, das zwischen den Substraten der Zelle eingekapselt ist, modifizieren.

The present invention is also directed to a method for producing so-called electro-optical display cells, in particular liquid-crystal cells, which comprise analogously to the electrochemical photovoltaic cells:

• At least a first, front, translucent substrate, the upper surface of which forms the front surface of the cell;
• At least one second, rear substrate, which may or may not be translucent and whose lower surface forms the rear surface of the cell;
• - Wherein the substrates each comprise on their surfaces facing each other at least one electrode, said electrodes being adapted to be connected to a control circuit of the display, which is capable of applying suitable voltages to selected electrodes, the transmission or reflection characteristics of a to modify the optically active environment;
• - wherein the substrates are united by an encapsulation frame which limits a dense volume for the encapsulation of the optically active environment, and
• - Connection means for establishing the electrical connection between each electrode and the control circuit of the display. A constant problem in the field of electrochemical photovoltaic cells of the type described above is posed by the connection means used to establish the electrical connection between the electrodes of the cell and an electrical supply circuit. This problem is also encountered in electro-optical display cells where the electrodes of the cell must be connected to the electrical control signal generator device which modifies the optical properties of the sensitive material encapsulated between the substrates of the cell.

The method that is most commonly used to make the connection areas that allow the electrodes of such In effect, connecting cells to an electronic supply or control circuit is to expose these connection regions along at least one edge of the cell where the substrate carrying the electrodes projects relative to the other substrate. Consequently, this solution leads to the cells of the cell having to be displaced relative to one another in order to be able to reach the electrodes and to establish the electrical connections. Such an arrangement makes the production of cells in series now difficult, especially if they are circular, and requires additional scratching and breaking operations of the glass, which are time consuming.

Around To eliminate these problems, a first solution was developed by the applicant in her patent application EP A1-0 936 496. This European patent application describes an electrochemical photovoltaic cell in which each one of the two substrates of the cell on the bulk of its surface translucent Electrode carries. Contact pads that are formed from an electrically conductive material are on created each electrode in the lateral contact zone, in the this with the cut surface of the substrate on which it was deposited, is flush.

By It is the features of the invention briefly described above possible, the surface the lateral electrical contact zone through which each electrode the cell connected to the electrical supply or control circuit is. The electrical connection between the electrodes and the electrical supply or control circuit is thus much more reliable.

The Deposition of the encapsulation frame, on the other hand, takes place by screen printing, a process that, we remember, from the deposition of one Paste-like consistency material through the unclogged material Mesh of a sieve, for example nylon or stainless steel Steel, with very fine mesh, with the help of a scraper, with the hand or mechanically operated will exist. Two major disadvantages now weigh on the procedure the deposition of encapsulation frames by screen printing. The first These disadvantages lie in the fact that it is difficult to final Dimensions of these frames with precision to control. When the upper substrate is applied to the lower substrate Namely, the encapsulating material is crushed and tends to become under the effect of exercised Spread the pressure so that the width of the encapsulation frame can only be controlled with an accuracy that typically in the order of magnitude a tenth of a millimeter lies. In addition, the inner wall faces the screen-printed encapsulation frame associated with the liquid crystal is in contact, usually shape irregularities so that these frames are at a sufficient distance from the Electrodes must be arranged so that they do not extend to the latter. Such Situation may be acceptable if over a sufficient space between the edges of the Cell from which the connections originate, and the actual active one Zone of the cell has becomes. Once tried, the dimensions of the connection to reduce the reserved dead zone to the surface of the Optimize display zone of the cell or space problems to respond is sufficient, the provided by the screen printing accuracy against it no longer.

Of the Another disadvantage of the method of deposition by screen printing is in the fact that the use of these methods creates mechanical constraints, which is not negligible are and often for the neighboring structures that have already been deposited at the moment in which the screen printing step takes place, are disadvantageous. Around To preserve fragile structures, it is preferable to post them deposit the deposit of the encapsulation frame. This is in the patent application EP-A1-0 936 496 the case in which the contact pads on the corresponding electrodes by means of a distributor of the syringe type be deposited, which is better known under its Anglo-Saxon name "Dispenser". But such a method is less accurate and limits the number from contact pads, whose manufacture is possible on one and the same cell, considerably what the use of this method on cells with a low density limited by connections.

By the European Patent EP-B1-0 708 931 on behalf of the South Korean company Samsung Electronics Co. Ltd. is also a liquid crystal display cell with thinner Compound and a manufacturing method for such a cell known. According to this Procedure becomes an encapsulation material strip on the perimeter deposited a first substrate whose dimensions are larger as those of the intended liquid crystal display cell. A second substrate of the same dimensions as the first substrate will follow deposited on the first substrate to create a cavity, through the first and second substrates and the encapsulant strip is limited. Thereafter, the encapsulating material is solidified, to connect the two substrates, then the cavity with the Liquid crystal filled via a filling opening, the subsequently is closed. After all becomes the entirety of the two substrates through the encapsulating material strip cut them to the dimensions of the wanted display cell bring to.

in the Samsung patent will help with the encapsulation material strip deposited a syringe. Consequently, it is necessary that the Contact pads are much less high than the space that the two substrates separates the cell, because if this is not the case, risking that overweight be observed at the places where the encapsulating material covers the contact pads, being the over thicknesses are unacceptable insofar as they lead to parallelism errors between the two Lead substrates and make the cell leaky. Since the contact pads are little are high, it is as well Required that they are wide enough to provide adequate electrical contact area to offer what the number of electrodes whose connection is possible and consequently the resolution the display thus obtained considerably limited.

The Patent Application US 2001/050748 describes a method for manufacturing a display cell with two substrates passing through an encapsulation layer which consists of a partition surrounding an encapsulating material is.

The The present invention has the object, the above-mentioned disadvantages of the prior art as well as still further to eliminate by they are a manufacturing process for an electro-optical cell, in particular a liquid crystal display cell, or an electrochemical photovoltaic cell with connecting means creates, which are intended to provide a reliable and less voluminous electrical Connection between the electrodes of the cell and an electrical Supply or control circuit.

The The present invention also has a method for producing a Cell of the aforementioned Kind to the subject, which is easy to use and above all the risks of deterioration of already deposited elements limited to the cell.

• – mindestens einem ersten, vorderen, lichtdurchlässigen Substrat, dessen obere Oberfläche die vordere Fläche der Zelle bildet;
• – mindestens einem zweiten, hinteren Substrat, das auch lichtdurchlässig sein kann oder nicht und dessen untere Oberfläche die hintere Fläche der Zelle bildet;
• – wobei die Substrate durch einen Einkapselungsrahmen verbunden sind, der ein Volumen für die Einkapselung eines empfindlichen Materials definiert, dessen physikalische, insbesondere optische, oder elektrische Eigenschaften geändert werden können;
• – wobei die Substrate jeweils auf ihren einander zugewandten Flächen wenigstens eine Elektrode umfassen, wobei diese Elektroden dazu vorgesehen sind, mit einer elektrischen Versorgungs- oder Steuerschaltung verbunden zu werden;
• – wobei sich die Elektroden der Zelle im Wesentlichen bis zu den Rändern der Zelle verlängern, um Verbindungsmittel zu bilden, um die elektrische Verbindung zwischen der Zelle und der Versorgungs- oder Steuerschaltung herzustellen.

To this end, the present invention relates to a method for producing an electro-optical cell, in particular a liquid-crystal display cell, or an electrochemical photovoltaic cell with:

• - At least a first, front, translucent substrate whose upper surface forms the front surface of the cell;
• At least one second, rear substrate, which may or may not be translucent, and whose lower surface forms the rear surface of the cell;
• - wherein the substrates are connected by an encapsulation frame defining a volume for the encapsulation of a sensitive material whose physical, in particular optical, or electrical properties can be changed;
• - Wherein the substrates each comprise on their surfaces facing each other at least one electrode, said electrodes being adapted to be connected to an electrical supply or control circuit;
• - wherein the electrodes of the cell extend substantially to the edges of the cell to form connecting means to establish the electrical connection between the cell and the supply or control circuit.

Of the Enclosure frame also includes at least one partition wall structured on one of the two substrates is and by its inner side surface the volume for encapsulation limited the sensitive material, said partition with respect to the margins returned to the cell runs, to break the connection contacts, and consequently of the Electrodes are crossed, the substrates by an encapsulation compound united, at least partially through the substrates and the outer side surface of the Partition wall limited clearance occupied, and the electrical connection means Contact pads comprise, which consist of an electrically conductive material, that on the extension from each electrode to the place where this is from the bulkhead exit, is created.

By these properties make it possible for the surface to increase the lateral electrical contact zone through which each electrode the cell with the electrical supply or control circuit connected is. The electrical connection between the electrodes and the supply or control circuit is thus much more reliable. On the other hand allows it is the fact that the encapsulation frame is made up of two parts becomes, namely one Partition that holds a volume for limited the encapsulation of the sensitive material, and a Encapsulation material strip deposited on the outer surface of the dividing wall and the empty space left between the two substrates due to the fact that the partition wall is slightly recessed with respect to the edges of the cell becomes, fills, the dimensions of the dead zone, for the connection of the cell reserved, considerably and consequently the surface of the cell's display zone to optimize or reduce their space requirements. Finally sheathed the encapsulation material the contact pads, which makes it possible any risk of worsening these pads too avoid.

• – auf jedem der Substrate die entsprechenden Eletroden zu strukturieren;
• – auf jeder Elektrode in dem Bereich, in dem diese Elektroden mit den Rändern der Zelle bündig sind, eine Kontaktanschlussfläche abzulagern, die aus einem elektrisch leitenden Material besteht;
• – auf einem der Substrate wenigstens eine Trennwand zu strukturieren, die durch ihre innere Seitenfläche das Volumen für die Einkapselung des empfindlichen Materials begrenzt;
• – das zweite Substrat mit dem ersten Substrat zu vereinigen;
• – ein Einkapselungsmaterial einzuleiten, das in den durch die Substrate und die äußere Seitenfläche der Trennwand begrenzten Freiraum fließen kann, bis zumindest ein Teil dieses Freiraums mit dem Einkapselungsmaterial belegt ist, und
• – das Einkapselungsmaterial zu verfestigen, damit dieses den Einkapse lungsrahmen der so erhaltenen Zelle bildet.

The present invention relates to a method for producing at least one cell of the aforementioned type, which method is characterized in that it comprises the steps which consist of:

• - to structure the corresponding electrodes on each of the substrates;
• Depositing on each electrode, in the region in which these electrodes are flush with the edges of the cell, a contact pad consisting of an electrically conductive material;
• - to structure on one of the substrates at least one partition, which limits the volume for the encapsulation of the sensitive material by its inner side surface;
• To combine the second substrate with the first substrate;
• To introduce an encapsulating material which can flow in the space bounded by the substrates and the outer side surface of the partition until at least a part of this space is occupied by the encapsulating material, and
• - To solidify the encapsulating material, so that it forms the Einkapse ment frame of the cell thus obtained.

Further Features and advantages of the present invention will become apparent from the following detailed description of an embodiment of the cell according to the invention more clearly, this example being purely for explanation and not for limitation in connection with the attached drawing is given, in the:

1 is a plan view of a cell, in particular the filling channel, which is to receive a liquid encapsulating material to form the encapsulation of this cell frame, and the corresponding supply hole for the encapsulating material is shown;

2 a perspective view of in 1 shown cell, wherein the upper glass substrate has been omitted for clarity;

3 is a perspective view with partial tearing of the upper substrate, which shows the volume, which is limited by the two superimposed substrates and the outer surface of a partition, which is produced according to the inventive method;

4 a sectional view of in 3 represented cell, and

5 is a schematic representation of a lot of cells.

The The present invention is apparent from the general inventive idea, which consists of the encapsulation frame of a cell, for example a liquid crystal cell, made of two parts, namely a partition that with a high accuracy near the edges of the Cell can be manufactured and inserted through its inner side surface Volume for the encapsulation of a sensitive material such as a liquid crystal limited, and an encapsulation compound in the free space is introduced between the two substrates and the resulting Encapsulation frame its mechanical resistance and its adhesion for the two Gives substrates. Consequently, it is possible to downsize the space, which is required to expose the electrodes of the cell, so that a more compact cell or a cell that has a larger active surface offers, is created. Since it was difficult with the encapsulation frame so far Accuracy was what it was necessary to arrange it sufficiently far from the edges of the cell, to be sure that the electrodes are correctly removed from the encapsulation frame leak, resulting in a substantial reduction of the active surface of the Cell led. Since the encapsulating material encases the conductive pads, which are formed at the end of the tracks, also any Risk avoided to worsen these lanyards.

The The present invention is related to a liquid crystal display cell described. It goes without saying that this example is given purely for explanation and that the present invention in an analogous manner for each type of electro-optical or electrochemical photovoltaic cell.

1 is a plan view of a liquid crystal cell 2 during manufacture, this cell being constituted by a total of two superimposed substrates 4 and 6 , For example, glass substrates, is formed, of which the front substrate 4 translucent while the rear substrate 6 also translucent or not.

In 1 is to see that the cell 2 a volume or a cavity 8th defined to contain the liquid crystals, this cavity 8th through the substrates 4 and 6 and through dense partitions 10 and 12 limited to receive an encapsulating material, the substrates 4 and 6 attached to each other, as will be described in more detail below. The front substrate 4 and the rear substrate 6 also carry a plurality of electrodes 14 or of counter electrodes 16 , As in 1 you can see these are the electrodes 14 and these counter electrodes 16 essentially rectilinear and extend perpendicular to each other. These electrodes 14 and 16 , which are shown in an exaggeratedly thinner manner to make the drawing more understandable, are intended to be connected to an electronic control circuit (not shown), which may be provided by the application of appropriate electronic control circuitry (not shown) electrical voltages to selected electrodes is capable of modifying the transmission or reflection properties of the composition for the light formed from the liquid crystal at the point of intersection of the electrodes under consideration. Of course, the shape and number of electrodes shown in the drawing are given by way of illustration only, of course many other arrangements of these electrodes may be considered.

The electrodes 14 and 16 the cell 2 extend to near the edges of the substrates 4 and 6 on which they are deposited to lanyard 18 to form the electrical connection between the cell 2 and the control circuit. The partition 12 on the other hand, is set back relative to the edges of the cell, around the connecting means 18 to interrupt, and is therefore from the electrodes 14 and 16 crosses.

The connecting means 18 are through contact pads 20 (in 2 and 3 more visible) made of an electrically conductive material that is based on the extension of each of the electrodes 14 and 16 created to the place where this from the dividing wall 12 escape. Through these contact pads 20 it is possible to increase the surface of the lateral electrical contact zone through which each electrode 14 or 16 is connected to the electronic control circuit. The electrical connection between the electrodes 14 and 16 and the control circuit is thus much more reliable.

According to a feature of the invention, the contact pads 20 less high than the space of the two substrates 4 and 6 and which is determined by the height of the encapsulation frame connecting these two substrates.

In the in 1 shown example, it can be seen that the dense partition 10 an outer contour between the two superimposed glass substrates 4 and 6 follows while the dividing wall 12 the inner contour of the liquid crystal cell 2 follows, leaving the outer partition wall 10 the inner partition 12 surrounds. Thus, these partitions stand 10 and 12 which are in the form of substantially vertical walls extending parallel to each other and at a distance from each other in direct contact with the one 10 with the outside atmosphere and for the other 12 with the liquid crystal. They advantageously form a filling channel 22 who in 1 and even better in 2 can be seen, with this channel 22 is intended to be filled with an encapsulating material around the encapsulation frame of the cell 2 to build. This is at least one hole 24 for the supply of the encapsulating material in the front substrate 4 formed and communicates with the filling channel 22 in contact while a hole 26 for the filling of the cavity 8th with the liquid crystal also in the front substrate 4 is bored. Because the filling channel 22 a large length depending on the geometry of the cell 2 may be divided into two or more channels, which are isolated by partition elements from each other and each have a corresponding filling hole 24 be filled. According to a variant, of course, at least one filling hole in the outer partition could 10 be formed.

It is natural to understand that the wall 10 can be omitted, leaving only the wall 12 which is in contact with the liquid crystal through its inner side surface. In this case, after structuring the wall 12 and positioning the upper substrate 4 on the lower substrate 6 the encapsulating material in the free space 28 initiated by the outer side surface of the partition wall 12 and the two superimposed substrates 4 and 6 is defined until at least part of the volume of this space 28 is occupied by the encapsulating material, as in 3 shown.

This process can be accomplished by means of a dispenser for encapsulating material, better known by its Anglo-Saxon term "dispenser". The manifold is along at least part of the circumference of the two substrates 4 and 6 moved to an encapsulating material strip 30 to be formed by joining the outer side surface of the dividing wall 12 supports and the two substrates 4 and 6 which forms the encapsulation frame. It is not necessary that the encapsulating material strip 30 extends to the edges of the cell. Suffice it to be sufficiently wide to play the role of an encapsulation framework, ie isolating the sensitive material from the external environment, as well as preventing it from exiting outside the cell and holding the entirety of the two substrates 4 and 6 ,

Around the encapsulating material strip 26 can also deposit one of the edges of the cell 2 passing through the two superimposed substrates 4 and 6 is limited, are immersed in a container containing a certain amount of this encapsulating material. The encapsulating material progressively fills the empty volume by capillarity 28 out, which is outside the scope of the partition 12 located. Another possibility is to introduce the encapsulating material between the two substrates 4 and 6 via a filling hole in one of the substrates 4 or 6 except half of the circumference of the partition 12 is bored.

According to the invention, after on the inner surface of one of the two substrates 4 or 6 All structures have been deposited, which are responsible for the following correct function of the cell 2 are required, such as the electrodes or the contact pads (these manufacturing steps will be described in detail later), this substrate covered with a photoresist material layer. This photoresist layer is then patterned by conventional photoetching techniques to give it the shape of the aforementioned filling channel 22 to lend, by the partitions 10 and 12 is limited. As soon as the filling channel 22 is obtained, the remaining substrate, which is also suitably trimmed, is combined with the first substrate. Of course, the order of these operations is given purely by way of illustration and could be modified insofar as the encapsulating material is introduced after the substrates have been combined.

According to a variant of the method, the photoresist layer is patterned to form not only the fill channel but also spacers (not shown in the drawing for clarity) that maintain a constant spacing between the two substrates 4 and 6 to maintain. The present invention thus makes it possible to structure the spacer structures and the filling channel in a single production step. In addition to the time and money savings that such a method allows to realize, another advantage of this embodiment of the method according to the invention lies in the fact that, since the spacers and the encapsulation frame are made simultaneously, the spacers no longer risk, at a later step Preparation of the encapsulation frame to be damaged, as was the case in the prior art. Finally, the filling channel and the spacers are made by means of the same material, which further simplifies the present process.

The photolithographic processes used in the present invention are conventional and well known to those skilled in the art. They consist essentially of sensitizing the photoresist layer by means of light which passes through the transparent zones of a screen reflecting the shapes of the zones to be sensitized. The photoresist material is also, in a very classical manner, a photosensitive resin which can be easily selected by a person skilled in the art and whose usual aim is to protect the surface of the layer to be etched from the action of a chemical reagent at the places where it is Resin after the sensitization by the optical radiation and chemical removal of the zones to be etched covering areas remains. As materials used to make the partitions 10 and 12 are well adapted, the photosensitive Cycloten from Dow Chemical and under the reference SU8 of MicroChem Corp. can be used. sold product.

As described above, after the structuring of the dense partition walls 10 and 12 that the filling channel 22 limit, and optionally the spacer the two substrates 4 and 6 united. Then the filling of the channel 22 be performed. This is done by creating a vacuum in the workspace where the cell 2 is trained, started. Once the vacuum is generated, a drop of encapsulating material is placed on the hole 24 deposited with the filling material 22 communicates. By capillarity, the encapsulation material begins to enter the channel 22 to flow. Then the atmospheric pressure in the working space is restored. Under the effect of the pressure difference between the filling channel, in which a sufficiently advanced vacuum prevails, and the atmospheric pressure, the encapsulating material is forced to the bottom of the filling channel.

Typically this is to encapsulate the cell 2 Material used a photosensitive resin in the liquid state in the filling channel 22 and then by sensitizing with the aid of ultraviolet light through the upper substrate 4 is polymerized through. The encapsulating material must have a hermetic seal on the edges of the cell 2 to effectively encapsulate the liquid crystal and protect it from diffusion phenomena of the ambient atmosphere gas. The encapsulating material must also have an adhesive power to enable the two substrates 4 and 6 to hold together. As a variant, the encapsulating material may also consist of a resin which polymerizes under the action of a temperature increase in the working space. As the encapsulating material, there may also be used a two-component adhesive whose components cure with time or under the effect of a temperature increase when brought together. As materials well adapted to the preparation of the encapsulation frame of the present invention, the products Loctite 3492 and Norland Optical Adhesives 61 can be cited. Another family of adhesives well adapted to the needs of the present invention is the cyanoacrylate adhesives. Finally, the thermoplastic resins can also be used in the invention.

Once the encapsulating material enters the filling channel 22 is initiated, then solidified, the liquid crystal in the cell 2 over the filling hole 26 be initiated. Advantageously, the introduction of the encapsulating material, its solidification, then the step of introducing the liquid crystal can be carried out successively or simultaneously in the same machine. Finally, the fill hole 26 for the liquid crystals as well as the room 32 that is in the immediate vicinity of the filling hole 26 is closed, to provide an encapsulation continuity with the next parts of the partition 12 to realize so that the encapsulation on the whole circumference of the cell 2 is completely realized. Finally, additional layers such as polarizers can still be found on the substrates 4 and 6 be deposited.

The electrodes 14 and 16 are usually prepared by photoetching in the form of thin layers of a transparent conductive oxide such as a mixture of indium / tin oxide, better known by its Anglo-Saxon name "indium tin oxide" or "ITO". After the step of structuring the electrodes 14 . 16 finds the step of making the contact pads 20 instead of. Of course, according to a variant, it would also be possible, first of all, to deposit a layer of conductive material, then to produce the contact pads on the surface of this layer and finally to pattern the conductive layer to form the electrodes.

The contact pads 20 are preferably, but not limited, formed by galvanic growth by means of a conductive material, such as gold. This is done by vapor deposition a gold layer on the entire surface of the two substrates 4 and 6 deposited. Before the deposition of the gold layer can be applied to the surface of the substrates 4 and 6 For example, a chromium layer are vapor-deposited, which is a better attachment of the gold layer on the surface of the substrates 4 and 6 allows. The gold layer is often called the growth layer or "seed layer" in the Anglo-Saxon terminology of the galvanic growth process.

After the vapor deposition of the gold layer, deposition of a layer of photoresist is performed in which openings are formed at locations where it is desired that the galvanic growth phenomenon take place, in other words, at the end of the electrodes 14 and 16 , The growth layer is electrically contacted to form the cathode, then the substrates become 4 . 6 immersed in a galvanic growth bath opposite a piece of a plate that plays the role of the anode. The bath is a base of gold (II) cyanide and potassium sold under the commercial name AURALL 292 by Lea Ronal. Under the effect of the application of an electric voltage, the electrochemical couple present in the solution in the electrochemical growth bath dissociates, and the gold is deposited at the locations of the substrates 4 and 6 not protected by the photoresist layer. Depending on the value of the electrical voltage and the time during which this voltage is applied, the rate of growth of the contact pads 20 to be controlled. If these contact pads 20 have reached their required dimensions, the electrical voltage is interrupted. Then only the immersion of the substrates remains 4 and 6 in chemical attack baths to sequentially remove the layers of photoresist, gold and chrome. When removing the gold layer, the contact pads 20 also slightly attacked and their height decreases by a value close to that of the thickness of the initial on the substrates 4 and 6 deposited gold layer. It should be noted that these various chemical attacks have no effect on the electrodes made of ITO 14 . 16 to have.

According to a variant, the contact pads 20 by means of a selective deposition process by printing such as screen printing by means of an adhesive material such as conductive particle-enriched epoxide.

After structuring the contact pads 20 be on the electrodes 14 . 16 Layers deposited to align the liquid crystal molecules. These alignment layers can be deposited by, for example, rubber pressure.

After the deposition of the alignment layers, the holes become 24 and 26 for the introduction of the encapsulating material and the liquid crystal into one of the substrates, here the front substrate 4 , drilled.

Subsequently, the structuring of the partition or partitions 10 and 12 Runaway leads in accordance with the mode described in detail above. At the same time as the partitions 10 and 12 Optionally, the spacer structures can be produced at the same time, for example, in the form of straight bars or blocks.

After the partitions 10 and or 12 are now structured, can now be the front substrate 4 on the back substrate 6 be applied and started, the filling channel 22 to fill. If only the inner partition 12 has been made, can the clearance 28 passing through the outer side surface of this partition 12 and the two match other laid substrates 4 and 6 is defined to be filled, for example, by one of the edges of the cell 2 is immersed in a container containing the liquid encapsulating material. By capillarity, the encapsulating material progressively fills the clearance 28 and envelops the contact pads 20 without any risk that they will deteriorate. In contrast, if the inner partition 12 and the outer partition 10 were structured simultaneously, thus the above-mentioned filling channel 22 form, the encapsulating material over the filling hole 24 in the front substrate 4 was formed in this channel 22 initiated.

Once the encapsulating material is solidified and the two substrates 4 and 6 are united in a permanent way, the cavity can 8th with the liquid crystal over the filling hole 26 that is in the upper substrate 4 is drilled, filled, then, when the filling is finished, the filling hole becomes 26 sealed by means of an adhesive plug, whereby all these operations can be carried out simultaneously in one and the same machine.

At this stage of the manufacturing process will be cutting the cell 2 For example, performed by sawing or cutting with water jet, a process that can follow a grinding step to the dimensions of the cell 2 to bring to their final dimensions. The saw is in 1 shown in dashed lines. It should be noted that in the example shown in the drawing, it passes through the contact pads 20 runs so that the cell has a regular contour, with lateral contact areas passing through the pads 20 are marked, have a large active surface area. Then you can click on the cut surface of the cell 2 through the openings of a mask tracks 34 which are used to connect the contact pads 20 in other words, the electrodes 14 and 16 , with Eingangsanschlussklem men an electronic control circuit (not shown), for example by means of conductive wires (also not shown) are used, which make it possible to contact the cut surface of the cell 2 easy to pick up.

The Invention applies to the production of a cell with more than two substrates, for example four, wherein the substrates are paired by an encapsulation frame be made up of at least one wall that holds the volume for encapsulation of sensitive material or liquid, as well as one Encapsulation material strip consists of the space between fills the two substrates considered, with pads from conductive material on the extension each electrode to the place where it exits the partition, are created. Likewise would be it is completely possible in consideration to draw that the contact pads are out of scope, which is bounded by the encapsulation strip.

It is to be understood that the invention is not limited to the embodiments just described, and that various simple modifications and variations can be contemplated without departing from the scope of the present invention. The present invention applies in particular analogously to a method for the serial production of cells, as in 5 shown. Such a lot of cells 2 includes two plates 36 and 38 that all cells 2 are common, and a network of dense partitions 10 and 12 that for each cell 2 a cavity 8th which is to contain the liquid crystals as well as filling channels to be filled with an encapsulating material around the two plates 36 and 38 to confine and to form the encapsulation frames. Advantageously, a first plurality of holes 26 for filling the cavities 8th with liquid crystal and a second plurality of holes 24 for the supply of the encapsulating material in the upper plate 36 educated. By this feature, it is possible to fill the filling channels not only from the side, for example, liquid crystal cells, but also from the top of the latter. Thus, one can work with a full batch of cells without being forced to divide that lot into bands to access the fill holes that are usually formed on either side of the cells. The cells 2 can therefore be completed in practice before cutting in lot. In particular, the filling and sealing of the feed holes 24 Consequently, for the encapsulating material which is to form the encapsulation frames of the cells, they should be carried out on the whole lot in a simpler and more economical manner than single cells. Likewise, the cells can 2 filled with liquid crystal and the filling holes 26 be closed while the cells are still in the lot.

Claims (17)

Method for producing an electro-optical cell, in particular a liquid crystal cell ( 2 ), or an electrochemical photovoltaic cell, comprising: - at least one light-transmitting first, front substrate ( 4 ) whose upper surface is the front surface of the cell ( 2 ) forms; At least a second, rear substrate ( 6 ), which may also be translucent or non-translucent and whose lower surface is the back surface of the cell ( 2 ) forms; - where the substrates ( 4 . 6 ) are connected by an encapsulation frame having a volume ( 8th ) For limits the encapsulation of a sensitive material whose physical, especially its optical or electrical properties can be changed; - where the substrates ( 4 . 6 ) on their surfaces facing each other at least one electrode ( 14 . 16 ), these electrodes ( 14 . 16 ) are intended to be connected to an electrical supply or control circuit, and - wherein the electrodes ( 14 . 16 ) of the cell ( 2 ) are extended substantially to the edges of the cell to connect means ( 18 ), which enable the electrical connection between the cell ( 2 In addition, this method covers the steps that consist in: - on each of the substrates ( 4 . 6 ) the corresponding electrodes ( 14 . 16 ) to structure; On one of the substrates ( 4 . 6 ) at least one partition wall ( 12 ), which with its inner side surface, the volume ( 8th ) for the encapsulation of the sensitive material, this partition ( 12 ) is recessed relative to the edges of the cell, such that it contacts the terminals ( 18 ), and thus from the electrodes ( 14 . 16 ) is crossed; The second substrate ( 4 ) with the first substrate ( 6 ) to unite; - to introduce an encapsulating material into the free space ( 28 ) flowing through the combined substrates ( 4 . 6 ) and the outer side surface of the partition ( 12 ), until at least part of said clearance is occupied by said encapsulating material, and - solidifying said encapsulating material so as to encapsulate said encapsulating frame of said cell thus obtained ( 2 ). A method according to claim 1, characterized in that it further comprises the step of allowing on each electrode ( 14 . 16 ) in the region in which these electrodes are flush with the edges of the cell, a contact pad ( 20 ), which is made of an electrically conductive material, and the cell ( 2 ) in such a way that it has a substantially flat sectional area with the lateral contact areas forming an increased active surface area. Method according to one of claims 1 or 2, characterized in that the penetration of the encapsulating material into the free space ( 28 ) is accomplished by capillarity. A method according to claim 1, characterized in that: - in the step consisting in structuring a partition in one of the substrates, a second partition wall ( 10 ), thereby defining at least one filling channel ( 22 ) bounded by the two partitions ( 10 . 12 ) is formed, which extend at a mutual distance; In the introduction of the encapsulating material, the free space is limited by the channel, such that the encapsulation material enters into the filling channel ( 22 ) flows until the entire volume of the filling channel ( 22 ) is occupied; - The cell is brought to their final dimensions by cutting through the thickness of the encapsulation frame. A method according to claim 4, characterized in that it further comprises the step of consisting, on each electrode ( 14 . 16 ) in the region in which these electrodes are flush with the edges of the cell, a contact pad ( 20 ), which is realized from an electrically conductive material, and the cell ( 2 ) in such a way that it has a substantially flat sectional area with the lateral contact areas having an increased active surface area. Method according to one of claims 4 or 5, characterized in that a lot of cells ( 2 ), the two plates common to all cells ( 36 . 38 ) and a network of partitions ( 10 . 12 ), which for each cell is a volume ( 8th ) for the encapsulation of the sensitive material, as well as filling channels ( 22 ), which are intended to be filled with an encapsulating material, around the two plates ( 36 . 38 ) and to form the encapsulation frames of the cells. Method according to claim 6, characterized in that in one of the plates ( 36 ) or ( 38 ) a first plurality of holes ( 26 ) for the filling of the volumes ( 8th ) with the sensitive material and a second plurality of holes ( 24 ) are formed for the supply of the encapsulating material. Method according to one of claims 4 to 7, characterized in that the penetration of the encapsulating material into the filling channel ( 22 ) is accomplished by capillarity. A method according to claim 8, characterized in that it comprises the steps consisting in: - in the filling channel ( 22 ) to create a vacuum; The encapsulating material in the filling channel ( 22 ), and - the pressure outside the cell ( 2 ), such that under the effect of the pressure difference between the filling channel ( 22 ), in which the vacuum prevails, and the ambient pressure, the encapsulating material is urged to the bottom of the filling channel. Method according to one of claims 1 to 9, characterized in that on one of the substrates ( 6 ) a layer of photoresist material is deposited, which is subsequently patterned by photoetching techniques to give it the shape of one or more partitions ( 10 . 12 ) to rent. A method according to claim 10, characterized in that the photoresist layer is structured in such a way that not only one or more partitions ( 10 . 12 ), but also spacer structures, which are provided between the two substrates ( 4 . 6 ) of the cell ( 2 ) to maintain a constant distance are formed. Method according to one of claims 1 to 11, characterized that the encapsulating material is selected from the group which is formed by resins by aid of sensitization of light or by heating by increasing the Temperature of the surrounding environment can be polymerized by thermoplastic resins, by cyanoacrylate adhesives and by two-component adhesives, whose components cure with time or under the effect of a temperature increase, when they are brought together. Method according to one of claims 2 to 12, characterized in that the contact pads ( 20 ) are formed by galvanic growth. Method according to claim 13, characterized in that the contact pads ( 20 ) are made of gold. Method according to one of claims 2 to 12, characterized that the contact pads be realized by selective printing. Method according to claim 15, characterized in that that a resin enriched with conductive particles is used gets to the contact pads manufacture. Method according to claim 16, characterized in that that the resin is an epoxy adhesive.